The present invention is related to application Ser. No. 09/682,951 entitled xe2x80x9cCompartment Venting For Gaseous Fueled Vehiclexe2x80x9d filed simultaneously herewith and incorporated by reference herein.
1. Technical Field
The present invention relates generally to combustible gaseous fuel powered vehicles, and more specifically, to a method and apparatus for ventilating the vehicle to prevent the build-up of the gaseous fuel therein.
2. Background
Liquid gasoline is the most commonly used fuel source for internal combustion engines for automotive vehicles. Liquid gasoline has a high volumetric density of energy and therefore may be easily transported. Automakers are increasingly investigating alternative sources for powering internal combustion engines, propane, natural gas and hydrogen.
One fuel increasingly being investigated is hydrogen fuel. Hydrogen fuel is lighter than air. Various components such as relief valves and pressure regulators are used in such system. If a hydrogen fuel leak occurs in these components, hydrogen can build up in the various compartments within the vehicle.
It would therefore be desirable to prevent the buildup of hydrogen or other gaseous fuel within the vehicle.
The present invention provides a ventilation system to prevent the buildup of gaseous fuel within the vehicle upon degradation of the performance of the various parts within the fuel distribution system. The vehicle system has a combustible gas fuel source within the vehicle. The ventilation system includes a fuel line coupling the engine and the gas source. A vent line is coupled to a vent. A pressure regulator and pressure relief valve are coupled between fuel line and vent line. An emergency vent line is attached to the pressure regulator (at the atmospheric vent hole), pressure relief valve and further down stream to an emergency burst disc. If the regulator fails, the high-pressure gas will vent from the atmospheric vent hole, through the vent line to the external vent. If the emergency vent hole becomes blocked, the down stream high-pressure by-pass valve would vent of excess pressure through the emergency vent line to the external vent. If both the regulator vent and by-pass vent were to fail, the downstream burst disc would relieve the excess pressure to the emergency vent line and external vent.
In a further aspect of the invention, a method for operating a ventilation system for an automotive vehicle comprises:
coupling a gaseous fuel storage tank to a fuel line;
providing a regulator coupled between the fuel line and a vent line;
providing a pressure relief valve coupled between the fuel line and a vent line; and
upon inoperability of either the regulator or pressure relief valve, coupling gaseous fuel to said vent line.
One advantage of the invention is that the system may be coupled to various components within the fuel system.
Other advantages and features of the present invention will become apparent when viewed in light of the detailed description of the preferred embodiment when taken in conjunction with the attached drawings and appended claims.